Breathing and altitude

My brother was contemplating a return visit to Ajijic after an 11 year absence. His Dr. thought he might have trouble breathing with the altitude, but he said there is a gum available here that could help. Does anyone know what he is talking about? Is there a "gum" that can help alleviate breathing problems at our altitude? If so, what is it and where is it available?

If he has COPD, the inflamation and production of phlegm can be helped by any decongestant and/or expectorant. In Mexico, Ambroxol is readily available and I found it very effective in 15-20 minutes. In more serious episodes, you can buy a loaded syringe of Celestone Soluspan at most farmacias and give yourself a shot in the butt, which will give relief lasting a couple of weeks, or more. It is a synthetic steroid anti-inflamatory. Unfortunately, neither of those are available to me here in Tucson, or I would still have them on hand.
That said; if the need for oxygen arises, OxyReyes at Lakeside can rent portable equipment while you are there.